Magneto



G. NATOLI July 3, 1923.

Filed Feb. 7 I

n 5. v mlm 32 Pajtented July 3, 1923.

GIUSEPPE NA'TOLI, OF TUBIN, ITALY.

i-ZAGNETO.

Application filed February 7, 1922. Serial No. 534,741.

To all whom it may concern.

Be itknown that I, GIUSEI'PE Narou, subject of the King of Italy, residing at Turin, Italy, have invented certain new and useful Improvements in Magnetos, of which the following is a specification.

The present invention relates to magnetos and particularly to magnetos for ignition purposes in explosion engines, of the kind comprising a stationary winding and a rotatable inductor consisting of a permanent magnet.

In the magneto according to this invention the magnetic flux passes directly from the poles of the magnet to the shoes of the winding core, without any bridge magnetic piece as at present used in the known magnetos of this kind.

Further the winding core is uninterrupted in the direction of the magnetic lines of force, said core being made either in a single piece or laminated.

The best efficiency is thus obtained in view of the fact that the air gap is restricted to that between the rotary magnet poles and the core shoes, this reducing the reluctance of the magnetic circuit.

The present invention comprises also other features relating to the magneto construction and mounting.

The annexed drawing shows by my of example an embodiment of this invention: wherein Figure 1 is a longitudinal central section of the ma neto; Figure 2 is a transverse section on hue 29 of Figure 1: Figure 3 is a fragmentary section on line 3-2 of Figure .2, with portions in side elevation.

As shown in the drawing, the magneto comprises a casing l in which is located a shaft 2 of non-magnetic material which is supported by ball bearings 14 and carries a permanent magnet 3. This magnet is U- shaped and is provided with an aperture through which projects the shaft 52 secured thereto by means of flanges or shoulders 4 and enlarged portion 5 and screws 13.

The winding (3 is located on a laminated core 7 each sheet of which has the contour as shown in Figure 2: said core providing extensions 7' which are engaged in a drum 8. the same extensions projecting through slots provided in the side portion of the drum and being clamped in position by means of a ring 9 screwed on the outer re stricted portion 8' of said drum.

The front and rear surfaces of the extensions 7 as well as the top and lower lips 8" projecting from the drum 8 are provided with a circular ridge 10 and the faces of the ring 9 and of the rear shoulder 8' of the drum 8 are provided wi h cooperating recesses, this arrangement ensuring a true centering and. a safe positioning of the winding core and extensions on the drum 8.

In the drum 8 is located one of the ball bearings 14 for the shaft 2, and the other one is located in another drum 12 which is connected to the first drum 8 by means of a sleeve 11 having inverted screw threads which cooperate with screw threads on the respective drums 8 and 12, so that by rotating the sleeve 11 the drums 9 and 12 may be clamped together to form a shell enclosing the magnet and its shaft.

Said shell 8 and 12 is mounted to rotate in the casing l of the magnet, and is pro vided with an actuating lever 16 for shifting it for the ignition advance, as well known.

It is of the utmost importance that the magnet has the shape shown by Figure 1, and that its portions facing the core shoes 7' have reduced cross section as compared with the remaining portion of toe same, because thisallows of reducing the size and weight of the magnetand of the whole apparatus whilst the flux value is not altered.

The magneto is provided with the other parts and devices for its operation. that is with primary and secondary windings shown as a whole by reference 6, as well as with a switch in the circuit of the primary winding which switch is controlled by a cam driven by the shall E2. the secondary winding lead ing to a current distributor having means for connection with the engine sparking plugs and driven by the gear 15 which is integral with the shaft 2. 'lhese parts and devices are not particularly described and illustrated, as they are well known and may be of any usual or approved construction.

It is to be noted that in the magneto according to this invention the magnet poles move in a very close proximiy to the end faces of the shoes 7 of the core 7 and that the air gap may be reduced to the minimum required for machining and mounting purposes; therefore it is possible to do away with the bridge pieces usually found in the stationary winding magnetos for obtaining the variations in the magnetic flux. and a single air gap is necessary.

Further the winding core may be made in a single piece or in a number of superimposed sheets each of which does not show interruptions cutting the path of the lines of force of the magnetic flux; this is an advantage in respect to the stationary magnet apparatus in which the poles of the magnet are provided with shoes connected thereto but separated therefrom.

Another advantage is secured by the described mounting of the magnet. and of its shaft, as in the present invention the shaft is in a single piece and it is well supported near its two ends.

Finally the described arrangement of the winding core provides large facilities for centering and mounting it.

hat I claim as my invention and desire to secure by United btates Letters Iatout is 1. In a magneto, a continuous shaft, shaped to provide an integral flange and an enlarged portion; means for rotatably suporting said shaft, a magnet fastened on said shaft, to said flange and enlarged portion, and a core having a winding thereon, said core being fastened to said shaft supporting means and having shoes embracing the poles of said magnet,

2. In a magneto, a. continuous shaft having integral flanges thereon: means for ro tatably supporting said shaft, a magnet fastened on said shaft by means of said flanges, and a c ntinuous laminated core fastened to said shal't supporting means and having a winding thereon and also having integral shoes embracing the poles of said magnet, said core and shot-s living uninterrupted in the direction of lln path of the rna; mcthlines of l'orvtlln-rcthrough'.

I). In a magneto. an integral shaft shaped to provide a flange and an enlarged portion, means for rotatahlv supporting said shaft at its ends. a U-shapcd magnet having an aperture thr ugh which said shaft projects, said magnet hcing lash-nod on said enlarged portion and said flange. and a corn having a winding thereon, lhc coril t-Ing tnstencd to said shaft upporting means and having shoes embracing the [soles of said magnet.

4. In a magneto, a continuous shaft, a magnet fastened on said shaft, a casing hav ing means for rotatably supporting said shaft and having apertures therein, a core carrying a winding and having shoes enibracing the poles of the magnet and entering said apertures, and a ring screwed on said casing adapted to clamp said shoes in position on said ring.

5. In a magneto, a continuous shaft. a magnet fastened on said shaft. a casing having means for rotatably supporting said shaft and havin apertures therein, a core carrying a winding and having shoes embracing the poles of the magnet and entering said apertures. a ring screwed on said casing adapted to clamp said shoes in position on said ring and cooperating centering ridges and grooves on the contacting faces of said casing. shoes and ring.

6. In a magneto, a continuous shaft, means for rotatably suporting said shaft, a drum carrying one of said means, a magnet fastened on said shaft, :1 core having a winding thereon and being fastened to said drum, said core having sh'oes embracing the poles of said magnet, a second drum carrying another supporting means for said shaft, means for connecting together said drums to provide a shell, means for rotatably supporting said shell, and means for actuating the said shell.

7. In a magneto, a continuous shaft, means for rotatably supporting said shaft, a magnet fastened on said shaft, and a core having a winding thereon, this core being fastened to said shaft supporting means and having shoes embracing the poles of said magnet. the portion of this magnet moving in register with said shoes having a restricted cross section as compared with its other remaining portion.

8. In a magnet a continuous shaft. 21 ma 'nct fastened on said shaft, a drum enclosing a. part of said shaft and magnet, another drum enclosing the remainder of the shaft and magnet and a sleeve for set-m ing the two drums togetlier.

In testimony whereof I afiix niv signature.

GIUsEPPn NATOLI. 

